In general, a motion picture film has an image recording area in the form of a series of frames at a longitudinal mid portion on both sides of which are bored film takeup openings (perforations). Between the image recording area and one of the sides formed with the perforations, there is linearly formed an analog sound track in which to record audio signals in an analog form.
With recent progress in digital technology, there is a move of digitally recording the audio information. Since the recording positions for the image recording area and the analog sound track are standardized by the Society of Motion Picture and Television Engineers (SMPTE) which is an association of motion picture and television engineers in the United States, the digitized audio information needs to be recorded in other areas than the above-mentioned image recording area or the analog sound track.
Thus, the conventional practice has been to use a redundant area between the right-hand side perforations and the right-hand side edge of the motion picture film as a digital sound track for the right channel and to use a redundant area between the left-hand side perforations and the left-hand side edge of the motion picture film as a digital sound track for the left channel, with the audio data being recorded linearly along the film proceeding direction.
Meanwhile, there is known such a data recording device for the motion picture film having, as a head portion, an LED array comprised of plural light emitting diodes (LEDs) in accordance with a data pattern.
With this data recording device for the motion picture film, the LEDs are lighted responsive to audio data. On lighting the LEDs, the electrical audio data are converted into light audio data which is illuminated via a recording lens on each digital sound track of the motion picture film. Thus, the motion picture film is sensitized responsive to the light audio data to record the audio data in a dot pattern.
In the data recording device for the motion picture film having such LED array in its head portion, in which the same current is caused to flow in each LED to light it, the same amount of light is not necessary produced from the LEDs due to differences in characteristics from one LED to another.
The effect due to light volume variations is manifested as burning variations of the recording patterns at the time of recording data on a negative film. These burning variations are responsible for printing variations at the time of preparation of positive films. If these positive films are reproduced by a film digital audio reproducing device, the SN ratio of the digital signal is worsened.
In view of the above-described status of the art, it is an object of the present invention to provide a data recording device for a motion picture film in which the negative film can be improved in quality inexpensively when recording digital audio data on a motion picture film.